Now, University of Washington researchers and their Finnish colleagues have made the first functioning bionic lens: a prototype with a single LED pixel, which could be safely worn by rabbits in the lab. (The image at right shows a rabbit wearing an earlier version of the lens, which contained a circuit but no light-emitting components.) Radio frequency energy emitted from a nearby transmitter and picked up by a circular antenna a fifth of an inch in diameter, printed on the lens, powered the electronics. The transmitter supplied adequate energy from three feet away when the lens was sitting in a dish, but had to be less than an inch away when the lens was placed on a rabbit’s eye, since tissues and fluids in the body interfered with reception. Since light from such a lens would be too close for the human eye to focus, the researchers made a separate contact composed of an array of smaller, flatter lenses, which would sit on top of the bionic contact and focus the light.